I still can't log in to connect even though I have tried the key given with the device, my account password and the password 'admin' advised in the device guide for the E5331 2b5b. I can't think of any other possibilities so I think I am just going to have to give up and accept that I wasted my $85 on the travel pack! Useless. It would have been nice if the person I asked in the Optus shop before I left had mentioned that the modem wouldn't automatically connect when I specifically asked if it would work just the same as at home and was told 'yes'. That isn't mentioned in any of the FAQs either. Even in My Account and Member Services nothing seems to help.
Really sorry for the delay. I've just responded to your other post here. Are you using an Optus modem and was this same modem working with another Optus SIM when in Australia?